// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include "gpuhelper.h"
#include "icosphere.h"
#include <GL/glu.h>
// PLEASE don't look at this old code... ;)

#include <algorithm>
#include <fstream>

GpuHelper gpu;

GpuHelper::GpuHelper()
{
	mVpWidth = mVpHeight = 0;
	mCurrentMatrixTarget = 0;
	mInitialized = false;
}

GpuHelper::~GpuHelper() {}

void
GpuHelper::pushProjectionMode2D(ProjectionMode2D pm)
{
	// switch to 2D projection
	pushMatrix(Matrix4f::Identity(), GL_PROJECTION);

	if (pm == PM_Normalized) {
		// glOrtho(-1., 1., -1., 1., 0., 1.);
	} else if (pm == PM_Viewport) {
		GLint vp[4];
		glGetIntegerv(GL_VIEWPORT, vp);
		glOrtho(0., vp[2], 0., vp[3], -1., 1.);
	}

	pushMatrix(Matrix4f::Identity(), GL_MODELVIEW);
}

void
GpuHelper::popProjectionMode2D(void)
{
	popMatrix(GL_PROJECTION);
	popMatrix(GL_MODELVIEW);
}

void
GpuHelper::drawVector(const Vector3f& position, const Vector3f& vec, const Color& color, float aspect /* = 50.*/)
{
	static GLUquadricObj* cylindre = gluNewQuadric();
	glColor4fv(color.data());
	float length = vec.norm();
	pushMatrix(GL_MODELVIEW);
	glTranslatef(position.x(), position.y(), position.z());
	Vector3f ax = Matrix3f::Identity().col(2).cross(vec);
	ax.normalize();
	Vector3f tmp = vec;
	tmp.normalize();
	float angle = 180.f / M_PI * acos(tmp.z());
	if (angle > 1e-3)
		glRotatef(angle, ax.x(), ax.y(), ax.z());
	gluCylinder(cylindre, length / aspect, length / aspect, 0.8 * length, 10, 10);
	glTranslatef(0.0, 0.0, 0.8 * length);
	gluCylinder(cylindre, 2.0 * length / aspect, 0.0, 0.2 * length, 10, 10);

	popMatrix(GL_MODELVIEW);
}

void
GpuHelper::drawVectorBox(const Vector3f& position, const Vector3f& vec, const Color& color, float aspect)
{
	static GLUquadricObj* cylindre = gluNewQuadric();
	glColor4fv(color.data());
	float length = vec.norm();
	pushMatrix(GL_MODELVIEW);
	glTranslatef(position.x(), position.y(), position.z());
	Vector3f ax = Matrix3f::Identity().col(2).cross(vec);
	ax.normalize();
	Vector3f tmp = vec;
	tmp.normalize();
	float angle = 180.f / M_PI * acos(tmp.z());
	if (angle > 1e-3)
		glRotatef(angle, ax.x(), ax.y(), ax.z());
	gluCylinder(cylindre, length / aspect, length / aspect, 0.8 * length, 10, 10);
	glTranslatef(0.0, 0.0, 0.8 * length);
	glScalef(4.0 * length / aspect, 4.0 * length / aspect, 4.0 * length / aspect);
	drawUnitCube();
	popMatrix(GL_MODELVIEW);
}

void
GpuHelper::drawUnitCube(void)
{
	static float vertices[][3] = { { -0.5, -0.5, -0.5 }, { 0.5, -0.5, -0.5 }, { -0.5, 0.5, -0.5 }, { 0.5, 0.5, -0.5 },
								   { -0.5, -0.5, 0.5 },	 { 0.5, -0.5, 0.5 },  { -0.5, 0.5, 0.5 },  { 0.5, 0.5, 0.5 } };

	glBegin(GL_QUADS);
	glNormal3f(0, 0, -1);
	glVertex3fv(vertices[0]);
	glVertex3fv(vertices[2]);
	glVertex3fv(vertices[3]);
	glVertex3fv(vertices[1]);
	glNormal3f(0, 0, 1);
	glVertex3fv(vertices[4]);
	glVertex3fv(vertices[5]);
	glVertex3fv(vertices[7]);
	glVertex3fv(vertices[6]);
	glNormal3f(0, -1, 0);
	glVertex3fv(vertices[0]);
	glVertex3fv(vertices[1]);
	glVertex3fv(vertices[5]);
	glVertex3fv(vertices[4]);
	glNormal3f(0, 1, 0);
	glVertex3fv(vertices[2]);
	glVertex3fv(vertices[6]);
	glVertex3fv(vertices[7]);
	glVertex3fv(vertices[3]);
	glNormal3f(-1, 0, 0);
	glVertex3fv(vertices[0]);
	glVertex3fv(vertices[4]);
	glVertex3fv(vertices[6]);
	glVertex3fv(vertices[2]);
	glNormal3f(1, 0, 0);
	glVertex3fv(vertices[1]);
	glVertex3fv(vertices[3]);
	glVertex3fv(vertices[7]);
	glVertex3fv(vertices[5]);
	glEnd();
}

void
GpuHelper::drawUnitSphere(int level)
{
	static IcoSphere sphere;
	sphere.draw(level);
}
